[¹¹C]labeled (±)-methyl jasmonate was synthesized using a C₁₈ Sep Pak™ at ∼100°C to sustain a solid-supported ¹¹C-methylation reaction of sodium (±)-jasmonate using [ ¹¹C]methyl iodide. After reaction, the Sep Pak was rinsed with acetone to elute the labeled product, and the solvent evaporated rendering [¹¹C]-(+)-methyl jasmonate at 96% radiochemical purity. The substrate, (±)-jasmonic acid, was retained on the Sep Pak so further chromatography was unnecessary. Total synthesis time was 25 min from the end of bombardment (EOB) which included 15 min to generate [¹¹C]methyl iodide using the GE Medical Systems PET Trace MeI system, 5 min for reaction and extraction from the cartridge, and 5 min to reformulate the product for plant administration. An overall radiochemical yield (at EOB) of 17 ± 4.3% was obtained by this process, typically producing 10mCi of purified radiotracer. A specific activity of 0.5 Ci/μmol was achieved using a short 3 min cyclotron beam to produce the starting ¹¹C.